Pathogenic potential of Escherichia coli from various sources in Port Harcourt, Rivers State, Nigeria

Despite its occurrence as a commensal, Escherichia coli is also notorious as a pathogen. One variation between these commensals and pathogens is the presence of specific factors one of which are the pathogenicity islands. One of the most commonly occurring of these is the PAI IV536. Potentially pathogenic species have been described in nonclinical settings. This often raises concerns on the role these environments play in transmission. This study therefore aimed at comparing the pathogenic ability of E. coli isolates from clinical and non-clinical sources based on the presence of the PAI IV536 marker. Thirty-five E. coli isolates were analyzed in this study. Following DNA extraction by boiling, the PAI IV536 gene fragment was amplified following standard procedure using the F5′-AAGGATTCGCTGTTACCGGAC-3′ and R5′-TCGTCGGGCAGCGTTTCTTCT-3′ primer pair. Of the 35 isolates, 13 were from clinical sources and 22 from nonclinical sources. In total, 25.7% (9/35) of the E. coli isolates in this study were found to possess the PAI IV536 gene. Clinical isolates had a much higher association of 61.5% with the PAI IV536 gene than non-clinical which only had a 4.5% representation of the PAI IV536 gene. This study reports on the detection of PAI IV536 in E. coli isolates from Port Harcourt, Rivers State Nigeria and a lower association of this pathogenicity marker with non-clinical isolates. Keywords: Escherichia coli, clinical vs non-clinical, pathogenicity, PAI IV53

Evaluation of antibacterial activity of hand sanitizers – an in vitro study

Hand hygiene, particularly hand sanitizing, is essential in reducing infectious disease transmission. The recent outbreak of Ebola in Nigeria both increased public awareness of the practice of hand sanitizing and resulted in the introduction of new products to the Nigerian market. This study set out to explore the actual antibacterial activity of these products against key clinical isolates using both dilution and diffusion susceptibility tests methods. Results showed higher inhibitory activity of the products to Klebsiella pneumoniae and Staphylococcus aureus than Escherichia coli and Pseudomonas aeruginosa. Overall the only local product tested had the least inhibitory activity. In general however, the sanitizers showed good activities, with inhibition of bacteria noted at concentrations as low as 25%. Products tested in this study showed higher zones of inhibition than previously reported, indicating their overall effectiveness. The variations in diffusion and dilution results highlight the effect of texture of the sanitizing product on testing methods and point at a need to properly assess if this could perhaps have any effect in real time on inhibitory activities. The hand sanitizing products tested in this study are suitable in disease prevention. However, regulatory bodies may need to focus on product texture until the effect of this on activity is determined.Keywords: Sanitizer, Nigeria, dilution, MIC, bacteriocida

Enterobacterial Repetitive Intergenic Consensus (ERIC) as a tool for genetic characterisation of bacterial isolates in Nigeria

Genetic characterisation as a tool for identification of bacterial isolates in Nigeria has been on the increase in recent years, and the 16s rRNA typing has been a preferred method. Due to cost limitations, there is a need to explore other genetic options. Enterobacterial Repetitive Intergenic Consensus (ERIC) polymerase chain reaction (PCR) analysis is a PCR- only based system which offers the advantage of reduced cost. This study set out to explore the use of ERIC-PCR in genetic characterisation of some selected bacterial isolates from Nigeria and compare it with genetic characterisation using 16s rRNA sequence typing. ERIC-PCR and 16s rRNA typing were carried out on 15 isolates following previously described protocols. Using 16s rRNA typing, thirteen different bacterial species were identified of which majority (85.7%) were Gram negative, with 57.1% belonging to the Enterobacteriaceae family. Using ERIC-PCR, only 13 of the 15 isolates (86.7%) could be typed, resulting in the identification of the 13 different types. ERIC-PCR was able to accurately differentiate between two members of the Proteus species, as well as identify the organisms as similar based on the banding pattern. The results show that ERIC-PCR may play a role as a bacterial identification tool but this role might be more suited to differentiating closely related members of a genus or typing within species rather than general bacterial identification. Keywords: Genetic characterisation, 16s rRNA, ERIC-PCR, Nigeri

Bacteriological analysis of water quality in a recreational park pond in Rivers State, Nigeria

Bacteriological analysis of a Recreational Park Pond in Port Harcourt was investigated to evaluate the water quality of the pond for recreational purposes. Samples collected from the pond were evaluated for physiochemical and bacteriological study. pH showed a slight alkaline range of 6.66 − 6.94 in sample A and D with a temperature range of 28.6 − 29oC. Samples evaluated for turbidity and salinity showed values of 0.309 − 0.784 NTU and 0.10ppt to 0.32ppt respectively. Similar bacteriological load ranging from 6.9 × 105cfu/ml − 2.1 × 106cfu/ml was observed, with coliform counts ranging from 3.4 × 105 − 1.3×106cfu/ml. Thirteen different bacterial genera were identified in total (Escherichia coli, Salmonella spp., Proteus spp., Citrobacter spp., Klebsiella spp, Bacillus spp., Serratia spp., Pseudomonas spp., Vibrio spp., Enterobacter spp., Staphylococcus aureus, Streptococcus spp., and Staphylococcus spp). Escherichia coli was the most commonly occurring group (14.7%) and Staphylococcus sp the least occurring (2.9%). Varying levels of resistance was noted against the 14 antibiotics tested, with the highest resistance noted against pefloxacin (55.9%)  while the lowest resistance was against erythromycin (2.9%). Majority of isolates (67.7%) however had MAR index values less than 0.21, indicative of a source related to low antibiotic use. Despite the association of potentially pathogenic bacteria with this water body, the low level of drug resistance associated with these organisms as well as the MAR index values, could point at these being environmental rather than human strains. Further molecular studies would be advised to confirm this.Keywords: Bacteriological analysis, recreational water, antibiotic resistance, pefloxaci

Molecular detection of mobilized colistin resistance (mcr-1) gene in Escherichia coli isolates from Port Harcourt, Nigeria

The emergence of plasmid borne colistin resistance in recent years has been problematic as a result of the potential for rapid dissemination through bacterial populations. This mcr-1 mediated resistance has been reported from around the globe and active surveillance is essential to monitor the developing issue. This study set out to determine the occurrence of such strains in a group of 60 Escherichia coli isolates using DNA extraction and amplification techniques. Following molecular confirmation of the identities of the E. coli isolates based on the detection of E. coli specific 16sRNA gene fragments, phenotypic colistin resistance of isolates was determined and isolates were screened for the mcr-1 gene using standard procedures. Of the 35 confirmed E. coli isolates, 60% were found to be colistin resistant, with a higher level of resistance noted among the non-clinical isolates. Plasmid mediated mcr-1 resistance was however found to be present in only 8.6% of total isolates, making up 14.3% of the colistin resistant strains. This mcr-1 mediated resistance was only noted in clinical isolates however. This detection of mcr-1 mediated colistin resistance in E. coli isolates from Port Harcourt, Nigeria is worrisome as it could point at a looming epidemic of colistin resistance and hence the development of untreatable bacterial isolates. Further studies are essential to properly assess the scope and spread of this situation.Keywords: Colistin resistance, mcr-1, Escherichia coli, Nigeri

Public Toilets in a tertiary institution in the Southern part of Nigeria as Potential Reservoirs of Drug Resistant Pathogens

Toilets have long been viewed as a significant potential contributor to human infectious diseases. Various studies worldwide have explored the bacterial communities associated with toilets but only few have focused on their possible role as reservoirs of drug resistant pathogens. To explore this role, four different surfaces from a pay-to-use toilet complex at a tertiary institution in the Southern part of Nigeria were sampled using the swab-rinse technique. Sample processing was done to determine bacterial load, identify bacterial types present in the samples and determine antibiotic susceptibility using standard techniques. Similar levels of bacterial contamination were observed at all the 14 sampling points ranging from 3.6×104 to 2.7×105 CFU. A higher level of contamination was generally noted on the door handles and floor surfaces. Of the ten different bacterial groups identified, Shigella sp. and Salmonella sp. were the predominant groups (20.6% each). The test isolates showed a wide rate of resistance to antibiotics, with the highest observed against ofloxacin (98.3%) and the least against ceftriaxone (44.4%). Forty-three different antibiogram patterns were detected among the test isolates. Most of the bacteria (63.2%) were associated with MAR index values greater than 0.8. This study shows that public toilets could play a role not just as a reservoir of potential pathogens but more specifically as a potential reservoir of drug resistant pathogenic microorganisms with high MAR indices. Keywords: Toilet, Reservoir, MAR index, Nigeri

River water quality assessment using environmentric techniques : case study of Jakara River Basin.

akara River Basin has been extensively studied to assess the overall water quality and to identify the major variables responsible for water quality variations in the basin. A total of 27 sampling points were selected in the riverine network of the Upper Jakara River Basin. Water samples were collected in triplicate and analyzed for physicochemical variables. Pearson product-moment correlation analysis was conducted to evaluate the relationship of water quality parameters and revealed a significant relationship between salinity, conductivity with dissolved solids (DS) and 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and nitrogen in form of ammonia (NH4). Partial correlation analysis (r p) results showed that there is a strong relationship between salinity and turbidity (r p = 0.930, p = 0.001) and BOD5 and COD (r p = 0.839, p = 0.001) controlling for the linear effects of conductivity and NH4, respectively. Principal component analysis and or factor analysis was used to investigate the origin of each water quality parameter in the Jakara Basin and identified three major factors explaining 68.11 % of the total variance in water quality. The major variations are related to anthropogenic activities (irrigation agricultural, construction activities, clearing of land, and domestic waste disposal) and natural processes (erosion of river bank and runoff). Discriminant analysis (DA) was applied on the dataset to maximize the similarities between group relative to within-group variance of the parameters. DA provided better results with great discriminatory ability using eight variables (DO, BOD5, COD, SS, NH4, conductivity, salinity, and DS) as the most statistically significantly responsible for surface water quality variation in the area. The present study, however, makes several noteworthy contributions to the existing knowledge on the spatial variations of surface water quality and is believed to serve as a baseline data for further studies. Future research should therefore concentrate on the investigation of temporal variations of water quality in the basin

Primary biodegradation and mineralization of hair shampoos in fresh, brackish and marine waters of the Niger Delta

Two methods, the methylene blue active stain (MBAS) river die away method for monitoring primary biodegradation of surfactants and the ultimate biodegradability method for monitoring mineralization of the total biodegradable organic component in a compound were employed to determine the biodegradability of three hair shampoos, (Hair fruit shampoo, New Goldmax super antidandruff shampoo and Goldmax antidandruff shampoo) for a 28-day period. Sodium dodecyl sulphate (SDS) served as the reference chemical. After 28 days, the percentages of MBAS remaining in fresh, brackish and marine waters respectively were: for hair fruits shampoo, 83.8, 95 and 2; for New Goldmax super antidandruff shampoo, 83.8, 80 and 12.5; for Goldmax antidandruff shampoo, 66.7, 59.5 and 17.3. However, the percentages of mineralization were: for carbon of hair fruit shampoo, 13.5, 8.6 and 95.2; for carbon of New Goldmax super antidandruff shampoo, 53.9,72.9 and 99.7, and for carbon of Goldmax antidandruff shampoo, 90.2, 83.2 and 99.8. Primary biodegradation and mineralization of SDS was independent of water type. The extent of both primary biodegradation and mineralization followed the trend: marine water > brackish water = fresh water. These results indicated that the extent of Primary biodegradation and mineralization was greatest with marine water of Bonny estuary and the two test methods produced the same results. Key words; Primary biodegradation, Mineralization, Shampoos, Freshwater, Brackish water, Marine water. [Global Jnl Environ Sci Vol.2(2) 2003: 88-95

Utilização de argilas esmectíticas do nordeste do Brasil para preparação de um adsorvente organofílico Utilization of smectit clays from the northeast of Brazil for preparing an organophilic adsorber

O principal objetivo foi a preparação e a utilização de uma argila organofílica com capacidade de promover a separação do composto fenol, encontrado em larga escala nos efluentes aquosos de indústrias petroquímicas. O trabalho consistiu no preparo de um material adsorvente, partindo de cinco tipos diferentes argilas retiradas de bacias localizadas na região nordeste do Brasil: Verde Lodo, Bofe e Chocolate, retiradas do município de Campina Grande, Boa Vista, PB; e Lagoa de Dentro e S. Jorge, do Pólo Gesseiro do Araripe, PE. As argilas in natura foram tratadas com uma solução de carbonato de sódio visando a troca dos poli-cátions existentes em suas regiões intercamadas pelo cátion sódio, em um reator de bancada, com diferentes concentrações, tempo de contato e temperatura, de acordo com um planejamento experimental 2³. Como resposta ao tratamento com carbonato de sódio, fez-se a leitura das viscosidades plásticas (cP ou mPa.s) das suspensões aquosas desse material com 4,86% em massa. Os resultados mostraram que a argila Chocolate, na melhor condição do planejamento experimental, atingiu uma viscosidade plástica de 4 mPa.s, sendo, portanto, escolhida como material adsorvente. Em seguida, este material foi submetido a um tratamento com sal quaternário de amônio em duas concentrações diferentes visando a troca catiônica de sódio por cátions amônio quaternário. Após o preparo do material adsorvente, foram realizados ensaios adsortivos de equilíbrio, sendo verificado o efeito da concentração do sal quaternário de amônio no processo adsortivo de remoção do fenol. A eficiência adsortiva, para uma relação de massa 1 g de argila organofílica e volume de solução fenólica igual a 100 mL, com concentrações iniciais entre 20 e 110 mg.L-1, foi de aproximadamente 70%.<br>The goal of this research was the preparation and use of organophilic clay capable of promoting the separation of phenol, found in large scale in the aqueous effluent of petrochemical industries. The studies consisted of preparing adsorbent material, based on five different types of clay taken from ponds located in the Northeast of Brazil, which are: Verde Lodo, Bofe and Chocolate, from Campina Grande, Boa Vista, PB, Brazil, and Lagoa de Dentro and S. Jorge, from Araripe's pole of plaster in PE, Brazil. In experimental scale the clays in natura were treated with a solution of sodium carbonate, to the exchange of poly-cations exist in their interlayer regions by the sodium cation, used different concentrations, temperature and time of contact, according to a experimental design 2³. In response to treatment with sodium carbonate, was reading the plastic viscosity (cP or mPa.s) of aqueous suspensions of this material with 4.86% by weight. The result showed that the Chocolate clay, in the best condition of the experimental design, has a plastic viscosity equal to 4 mPa.s and therefore was chosen as adsorbent material to continue the study. The Chocolate clay was subjected to a treatment with quaternary aµmonium salt, in two different concentrations, to cation exchange of sodium by quaternary aµmonium cations. After preparing the adsorbent material, were tested adsorptive equilibrium was verified the effect of the concentration of the quaternary aµmonium salt in the adsorptive process to removal of phenol. The adsorptive efficiency for a ratio (wt/vv) of 1 g of organophilic clay in 100 mL of phenolic solution, with initial concentrations between 20 and 110 mg.L-1, was approximately 70%